Hello Himal Prasad Ghimiray,
Commit 09ba0a8f06cd ("drm/xe/svm: Implement prefetch support for SVM
ranges") from May 13, 2025 (linux-next), leads to the following
Smatch static checker warning:
drivers/gpu/drm/xe/xe_vm.c:2922 prefetch_ranges()
warn: passing positive error code
's32min-(-96),(-94)-(-15),(-13)-(-12),(-10)-(-2),1' to 'ERR_PTR'
drivers/gpu/drm/xe/xe_vm.c
2917
2918 err = xe_svm_range_get_pages(vm, svm_range, &ctx);
2919 if (err) {
2920 if (err == -EOPNOTSUPP || err == -EFAULT ||
err == -EPERM)
2921 err = -ENODATA;
--> 2922 drm_dbg(&vm->xe->drm, "Get pages failed,
asid=%u, gpusvm=%p, errno=%pe\n",
2923 vm->usm.asid, &vm->svm.gpusvm,
ERR_PTR(err));
The comments on walk_page_range() say it can return > 0 on success but
the comments on hmm_range_fault() say it can never return > 0. Smatch
does a naive reading of the code and thinks that it can return > 0.
Presumably the comments are correct but the code is too tricky for me.
I can easily silence this in Smatch by adding deleting the positive
returns from hmm_range_fault() from the cross function DB. Can someone
confirm that's the correct thing to do?
2924 return err;
2925 }
2926 xe_svm_range_debug(svm_range, "PREFETCH - RANGE GET
PAGES DONE");
2927 }
2928
2929 return err;
2930 }
regards,
dan carpenter
